Issue #5137 - Restoring clashing resource test

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>

jetty-webapp/src/test/java/org/eclipse/jetty/webapp/WebAppClassLoaderTest.java

@@ -27,6 +27,7 @@
 import java.security.ProtectionDomain;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Enumeration;
 import java.util.List;
 
 import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
@@ -38,11 +39,11 @@
 
 import static org.eclipse.jetty.toolchain.test.ExtraMatchers.ordered;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.anyOf;
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assumptions.assumeTrue;
@@ -346,23 +347,19 @@ public void testClashingResource() throws Exception
         // The existence of a URLStreamHandler changes the behavior
         assumeTrue(URLStreamHandlerUtil.getFactory() == null, "URLStreamHandler changes behavior, skip test");
 
-        // This cannot test order of resources from the URLClassLoader, as there is no
-        // guarantee of order from any Java ClassLoader.
-        // It can only test if both resources are being returned (in any order).
-
-        List<URL> resources = Collections.list(_loader.getResources("org/acme/clashing.txt"));
-        assertThat("Resource clashing count", resources.size(), is(2));
-
-        for (URL url : resources)
+        Enumeration<URL> resources = _loader.getResources("org/acme/clashing.txt");
+        assertTrue(resources.hasMoreElements());
+        URL resource = resources.nextElement();
+        try (InputStream data = resource.openStream())
         {
-            try (InputStream data = url.openStream())
-            {
-                assertThat("correct contents of " + url, IO.toString(data),
-                    anyOf(
-                        is("alpha"),
-                        is("omega")
-                    ));
-            }
+            assertThat("correct contents of " + resource, IO.toString(data), is("alpha"));
+        }
+        assertTrue(resources.hasMoreElements());
+        resource = resources.nextElement();
+        try (InputStream data = resource.openStream())
+        {
+            assertThat("correct contents of " + resource, IO.toString(data), is("omega"));
         }
+        assertFalse(resources.hasMoreElements());
     }
 }